#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for (int i = (s); i < (int)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for (int i = (int)(s - 1); i >= (int)(e); i--)
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;

template <typename T, typename U>
T chmax(T& a, const U& b) {
    if (a >= b) return false;
    a = b;
    return true;
}
template <typename T, typename U>
T chmin(T& a, const U& b) {
    if (a <= b) return false;
    a = b;
    return true;
}

void yes_no(bool f, string yes = "Yes", string no = "No") { cout << (f ? yes : no) << "\n"; }

void solve() {
    int n, m, k;
    cin >> n >> m >> k;
    const ll inf = 1e18;
    vector<vl> d(n, vl(n, inf));
    rep(i, n) d[i][i] = 0LL;
    rep(i, m) {
        int a, b;
        cin >> a >> b;
        --a;
        --b;
        d[a][b] = 1;
        d[b][a] = 1;
    }
    rep(k, n) rep(i, n) rep(j, n) chmin(d[i][j], d[i][k] + d[k][j]);
    auto jd = [&](vi v) {
        int n = v.size();
        vector dp(1 << n, vl(n, inf));
        dp[1][0] = 0;
        REP(mask, 1, 1 << n)
        rep(id, n) if (mask & (1 << id)) {
            int cur = v[id];
            rep(i, n) if ((mask & (1 << i)) == 0) {
                int nxt = v[i];
                chmin(dp[mask | (1 << i)][i], dp[mask][id] + d[cur][nxt]);
            }
        }
        int tot = (1 << n) - 1;
        rep(i, n) if (dp[tot][i] <= k) return true;
        return false;
    };
    vi v;
    v.emplace_back(0);
    ll ans = 0;
    REPR(i, n, 1) {
        v.emplace_back(i);
        if (!jd(v)) v.pop_back();
        else ans += (1LL << i) - 1;
    }
    cout << ans << "\n";
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int t = 1;
    // cin >> t;
    rep(ti, t) solve();
    return 0;
}